diff --git a/src/idp_test/__init__.py b/src/idp_test/__init__.py
index 61381c5..a061511 100644
--- a/src/idp_test/__init__.py
+++ b/src/idp_test/__init__.py
@@ -6,6 +6,7 @@ import pprint
 import types
 import argparse
 import sys
+import six
 
 import logging
 import imp
@@ -356,7 +357,7 @@ class SAML2client(object):
             item = {"id": key, "name": val["name"]}
             try:
                 _desc = val["descr"]
-                if isinstance(_desc, basestring):
+                if isinstance(_desc, six.string_types):
                     item["descr"] = _desc
                 else:
                     item["descr"] = "\n".join(_desc)
@@ -377,7 +378,7 @@ class SAML2client(object):
                 item = {"id": key, "name": val["name"]}
                 try:
                     _desc = val["descr"]
-                    if isinstance(_desc, basestring):
+                    if isinstance(_desc, six.string_types):
                         item["descr"] = _desc
                     else:
                         item["descr"] = "\n".join(_desc)
diff --git a/src/idp_test/interaction.py b/src/idp_test/interaction.py
index 03da9c2..2fbc46b 100644
--- a/src/idp_test/interaction.py
+++ b/src/idp_test/interaction.py
@@ -2,6 +2,7 @@ __author__ = 'rohe0002'
 
 import json
 import logging
+import six
 
 from urlparse import urlparse
 from bs4 import BeautifulSoup
@@ -34,7 +35,8 @@ def pick_interaction(interactions, _base="", content="", req=None):
                     _match += 1
                 else:
                     _c = _bs.title.contents
-                    if isinstance(_c, list) and not isinstance(_c, basestring):
+                    if isinstance(_c, list) and not isinstance(
+                      _c, six.string_types):
                         for _line in _c:
                             if val in _line:
                                 _match += 1
@@ -165,7 +167,7 @@ def pick_form(response, url=None, **kwargs):
                         _default = _ava["value"]
                         try:
                             orig_val = form[prop]
-                            if isinstance(orig_val, basestring):
+                            if isinstance(orig_val, six.string_types):
                                 if orig_val == _default:
                                     _form = form
                             elif _default in orig_val:
diff --git a/src/saml2/entity.py b/src/saml2/entity.py
index 6eed861..34b3e90 100644
--- a/src/saml2/entity.py
+++ b/src/saml2/entity.py
@@ -4,6 +4,7 @@ import logging
 from hashlib import sha1
 from Crypto.PublicKey import RSA
 import requests
+import six
 from saml2.metadata import ENDPOINTS
 from saml2.profile import paos, ecp
 from saml2.soap import parse_soap_enveloped_saml_artifact_resolve
@@ -156,7 +157,7 @@ class Entity(HTTPBase):
         self.sec = security_context(self.config)
 
         if virtual_organization:
-            if isinstance(virtual_organization, basestring):
+            if isinstance(virtual_organization, six.string_types):
                 self.vorg = self.config.vorg[virtual_organization]
             elif isinstance(virtual_organization, VirtualOrg):
                 self.vorg = virtual_organization
diff --git a/src/saml2/httpbase.py b/src/saml2/httpbase.py
index 79d4ba0..2da045f 100644
--- a/src/saml2/httpbase.py
+++ b/src/saml2/httpbase.py
@@ -1,4 +1,5 @@
 import calendar
+import six
 from six.moves import http_cookiejar
 import copy
 import re
@@ -260,7 +261,7 @@ class HTTPBase(object):
         :param typ: Whether a Request, Response or Artifact
         :return: dictionary
         """
-        if not isinstance(message, basestring):
+        if not isinstance(message, six.string_types):
             message = "%s" % (message,)
 
         return http_form_post_message(message, destination, relay_state, typ)
@@ -375,7 +376,7 @@ class HTTPBase(object):
         :param key: Key to use for signing
         :return: dictionary
         """
-        if not isinstance(message, basestring):
+        if not isinstance(message, six.string_types):
             message = "%s" % (message,)
 
         return http_redirect_message(message, destination, relay_state, typ,
diff --git a/src/saml2/ident.py b/src/saml2/ident.py
index 0420747..c7090bc 100644
--- a/src/saml2/ident.py
+++ b/src/saml2/ident.py
@@ -1,6 +1,7 @@
 import copy
 import shelve
 import logging
+import six
 
 from hashlib import sha256
 from urllib import quote
@@ -66,7 +67,7 @@ class IdentDB(object):
      Keeps a list of all nameIDs returned per SP
     """
     def __init__(self, db, domain="", name_qualifier=""):
-        if isinstance(db, basestring):
+        if isinstance(db, six.string_types):
             self.db = shelve.open(db)
         else:
             self.db = db
@@ -94,7 +95,7 @@ class IdentDB(object):
         :param ident: user identifier
         :param name_id: NameID instance
         """
-        if isinstance(ident, unicode):
+        if isinstance(ident, six.string_types):
             ident = ident.encode("utf-8")
 
         # One user may have more than one NameID defined
diff --git a/src/saml2/pack.py b/src/saml2/pack.py
index f045c7a..7c6b957 100644
--- a/src/saml2/pack.py
+++ b/src/saml2/pack.py
@@ -20,6 +20,7 @@ import logging
 from saml2.sigver import REQ_ORDER
 from saml2.sigver import RESP_ORDER
 from saml2.sigver import SIGNER_ALGS
+import six
 
 logger = logging.getLogger(__name__)
 
@@ -57,7 +58,7 @@ def http_form_post_message(message, location, relay_state="",
     """
     response = ["<head>", """<title>SAML 2.0 POST</title>""", "</head><body>"]
 
-    if not isinstance(message, basestring):
+    if not isinstance(message, six.string_types):
         message = "%s" % (message,)
 
     if typ == "SAMLRequest" or typ == "SAMLResponse":
@@ -94,7 +95,7 @@ def http_redirect_message(message, location, relay_state="", typ="SAMLRequest",
     :return: A tuple containing header information and a HTML message.
     """
 
-    if not isinstance(message, basestring):
+    if not isinstance(message, six.string_types):
         message = "%s" % (message,)
 
     _order = None
@@ -163,7 +164,7 @@ def make_soap_enveloped_saml_thingy(thingy, header_parts=None):
     body.tag = '{%s}Body' % NAMESPACE
     envelope.append(body)
 
-    if isinstance(thingy, basestring):
+    if isinstance(thingy, six.string_types):
         # remove the first XML version/encoding line
         logger.debug("thingy0: %s" % thingy)
         _part = thingy.split("\n")
diff --git a/src/saml2/s2repoze/plugins/sp.py b/src/saml2/s2repoze/plugins/sp.py
index bd05a06..2088a5f 100644
--- a/src/saml2/s2repoze/plugins/sp.py
+++ b/src/saml2/s2repoze/plugins/sp.py
@@ -12,6 +12,7 @@ import platform
 import shelve
 import traceback
 import saml2
+import six
 from urlparse import parse_qs, urlparse
 from saml2.md import Extensions
 from saml2 import xmldsig as ds
@@ -555,7 +556,7 @@ class SAML2Plugin(object):
     def add_metadata(self, environ, identity):
         """ Add information to the knowledge I have about the user """
         name_id = identity['repoze.who.userid']
-        if isinstance(name_id, basestring):
+        if isinstance(name_id, six.string_types):
             try:
                 # Make sure that userids authenticated by another plugin
                 # don't cause problems here.
diff --git a/src/saml2/sigver.py b/src/saml2/sigver.py
index cbeec97..2ff13fc 100644
--- a/src/saml2/sigver.py
+++ b/src/saml2/sigver.py
@@ -15,6 +15,7 @@ import urllib
 
 from time import mktime
 from binascii import hexlify
+import six
 
 from Crypto.PublicKey.RSA import importKey
 from Crypto.Signature import PKCS1_v1_5
@@ -728,7 +729,7 @@ class CryptoBackendXmlSec1(CryptoBackend):
 
     def __init__(self, xmlsec_binary, **kwargs):
         CryptoBackend.__init__(self, **kwargs)
-        assert (isinstance(xmlsec_binary, basestring))
+        assert (isinstance(xmlsec_binary, six.string_types))
         self.xmlsec = xmlsec_binary
         if os.environ.get('PYSAML2_KEEP_XMLSEC_TMP', None):
             self._xmlsec_delete_tmpfiles = False
@@ -1353,7 +1354,7 @@ class SecurityContext(object):
                 _certs = []
             certs = []
             for cert in _certs:
-                if isinstance(cert, basestring):
+                if isinstance(cert, six.string_types):
                     certs.append(make_temp(pem_format(cert), suffix=".pem",
                                            decode=False,
                                            delete=self._xmlsec_delete_tmpfiles))
diff --git a/src/saml2test/check.py b/src/saml2test/check.py
index 2433e31..7109371 100644
--- a/src/saml2test/check.py
+++ b/src/saml2test/check.py
@@ -1,5 +1,6 @@
 import inspect
 import json
+import six
 
 __author__ = 'rolandh'
 
@@ -91,7 +92,7 @@ class ResponseInfo(Information):
         self._status = self.status
         _msg = conv.last_content
 
-        if isinstance(_msg, basestring):
+        if isinstance(_msg, six.string_types):
             self._message = _msg
         else:
             self._message = _msg.to_dict()
diff --git a/src/saml2test/interaction.py b/src/saml2test/interaction.py
index 0121fbc..ddfbeac 100644
--- a/src/saml2test/interaction.py
+++ b/src/saml2test/interaction.py
@@ -2,6 +2,7 @@ __author__ = 'rohe0002'
 
 import json
 import logging
+import six
 
 from urlparse import urlparse
 from bs4 import BeautifulSoup
@@ -125,8 +126,8 @@ class Interaction(object):
                         _match += 1
                     else:
                         _c = _bs.title.contents
-                        if isinstance(_c, list) and not isinstance(_c,
-                                                                   basestring):
+                        if isinstance(_c, list) and not isinstance(
+                          _c, six.string_types):
                             for _line in _c:
                                 if val in _line:
                                     _match += 1
@@ -186,7 +187,7 @@ class Interaction(object):
                             _default = _ava["value"]
                             try:
                                 orig_val = form[prop]
-                                if isinstance(orig_val, basestring):
+                                if isinstance(orig_val, six.string_types):
                                     if orig_val == _default:
                                         _form = form
                                 elif _default in orig_val:
diff --git a/src/saml2test/opfunc.py b/src/saml2test/opfunc.py
index 2f88c70..2d612ed 100644
--- a/src/saml2test/opfunc.py
+++ b/src/saml2test/opfunc.py
@@ -1,5 +1,6 @@
 import logging
 import json
+import six
 
 from urlparse import urlparse
 
@@ -163,7 +164,7 @@ def pick_form(response, content, url=None, **kwargs):
                         _default = _ava["value"]
                         try:
                             orig_val = form[prop]
-                            if isinstance(orig_val, basestring):
+                            if isinstance(orig_val, six.string_types):
                                 if orig_val == _default:
                                     _form = form
                             elif _default in orig_val:
diff --git a/src/saml2test/tool.py b/src/saml2test/tool.py
index 6071408..d911359 100644
--- a/src/saml2test/tool.py
+++ b/src/saml2test/tool.py
@@ -3,6 +3,7 @@ import sys
 import traceback
 import logging
 from urlparse import parse_qs
+import six
 
 from saml2test.opfunc import Operation
 from saml2test import CheckError, FatalError
@@ -64,7 +65,7 @@ class Conversation(object):
             raise CheckError
 
     def do_check(self, test, **kwargs):
-        if isinstance(test, basestring):
+        if isinstance(test, six.string_types):
             chk = self.check_factory(test)(**kwargs)
         else:
             chk = test(**kwargs)
diff --git a/src/sp_test/base.py b/src/sp_test/base.py
index eaea070..1ed778c 100644
--- a/src/sp_test/base.py
+++ b/src/sp_test/base.py
@@ -5,6 +5,7 @@ import os
 import traceback
 import urllib
 import sys
+import six
 
 from urlparse import parse_qs
 from saml2 import BINDING_HTTP_REDIRECT, class_name
@@ -93,7 +94,7 @@ class Conversation():
             raise CheckError
 
     def do_check(self, test, **kwargs):
-        if isinstance(test, basestring):
+        if isinstance(test, six.string_types):
             chk = self.check_factory(test)(**kwargs)
         else:
             chk = test(**kwargs)